Molecular sievesmuaj qhov tshwj xeeb siab affinity rau dej thiab muaj zog nqus dej zog, yog li lawv tau dav siv rau cov roj kom qhuav thiab yog ib qho zoo tagnrho ziab tus neeg sawv cev. Cov kev sim tau pom tias cov roj argon tsis tu ncua qhuav los ntawm Mg (CIO4) 2, P2O3 thiab nws yog xim hlau sodium tsis zoo li qhov ziab los ntawm molecular sieves. Meanwhile, molecular sieves yog ruaj khov nyob rau hauv cov xwm, tsis ntshai ntawm tshav kub, tsis ntshai dej, tsis eroded los ntawm ntau yam kuab tshuaj, thiab yuav tsum regenerated ntau lub sij hawm thaum tseem tuav zoo adsorption kev ua tau zoo, thiab yuav siv tau rau lub sij hawm ntev. Qhov zoo ntawm kev siv molecular sieves rau roj ziab yog raws li nram no:
(1) Lub tshuab ziab khaub ncaws yog qhov siab heev. Tom qab cov roj tau qhuav los ntawm molecular sieves, cov khoom lag luam uas tsis tshua muaj qis qis tuaj yeem tau txais, thiab tsis tas yuav muaj lwm yam khoom siv khov kho. Cov lwg taw tes ntawm huab cua tom qab molecular sieve ziab tuaj yeem qis li -60 txog -90 degree, thaum siv lwm cov tshuaj ziab khaub ncaws xws li alumina lossis silica rau huab cua kom qhuav, lub lwg taw tes tsuas yog ncav cuag -60 degree.
(2) Muaj peev xwm ziab kom qhuav rau cov pa roj nrog cov av qis. Thaum kho cov roj compressed nrog cov av qis lossis cov roj uas tsis tau qhuav tag, qhov adsorption efficiency ntawm molecular sieves yog ntau dua li ntawm lwm cov adsorbents. Qhov qis dua cov dej vapor ntsiab lus, qhov tseem ceeb dua cov yam ntxwv ntawm molecular sieves. Piv txwv li, ntawm qhov txheeb ze av noo ntawm 1%, lub peev xwm adsorption ntawm molecular sieves tuaj yeem ncav cuag 18% ntawm nws tus kheej qhov hnyav, uas yog 10 npaug siab dua li ntawm activated alumina thiab 20 npaug siab dua li ntawm silica gel. Yog li ntawd, siv molecular sieves kom tshem tawm cov kab dej los ntawm cov pa roj yog qhov zoo heev.
(3) Muaj zog nqus dej ua haujlwm ntawm qhov kub thiab txias. Rau kev ziab ntawm high -kub gases, siv molecular sieves rau lub cev qhuav dej yog qhov zoo tshaj plaws. Piv txwv li, ntawm 100 degree, rau huab cua nrog ib tug txheeb ze av noo ntawm 1.3%, molecular sieves tuaj yeem adsorb mus txog 15% ntawm qhov sib npaug ntawm cov dej, uas yog 10 npaug siab dua activated alumina thiab 20 npaug siab dua silica gel.
Thaum cov adsorbents adsorb dej, lawv txhua tus tso cov cua sov latent. Qhov no adsorption tshav kub ua rau lub txaj kub nce, yog li txo qhov muaj peev xwm adsorption ntawm cov adsorbent. Txawm li cas los xij, lub peev xwm adsorption ntawm molecular sieves tsis tshua cuam tshuam los ntawm kev hloov pauv hauv txaj. Yog li ntawd, qee zaum nws tsis tas yuav tsum tos kom txog thaum lub txaj txheej yog txias tag ua ntej siv nws tom qab kev tsim dua tshiab.
(4) Kev ziab kom qhuav zoo ntawm cov roj nrawm nrawm
Nyob rau hauv high gas velocities, molecular sieves kuj muaj peev xwm adsorption zoo rau roj ziab. Piv txwv li, ntawm cov pa roj tsawg, lub peev xwm ziab ntawm silica gel thiab molecular sieves zoo ib yam; Thaum cov roj tshaj tawm nce, lub peev xwm adsorption ntawm silica gel poob qis, thaum cov molecular sieves tsuas yog txo me ntsis.
(5) Muaj peev xwm adsorb lwm yam impurity molecules
Molecular sieves tuaj yeem tshem tawm cov impurities uas tsis yog dej los ntawm cov roj. Txawm hais tias lub peev xwm adsorption ntawm molecular sieves rau dej muaj zog ntau dua li lwm cov roj impurities, tsuav yog tsim nyog, dej thiab lwm yam impurities tuaj yeem raug tshem tawm ib txhij siv molecular sieves.
(6) Xaiv adsorption
Hauv ntau qhov kev ua kom qhuav, cov khoom siv hauv cov khoom siv raw kuj feem ntau adsorbed thaum lub cev qhuav dej. Yog li ntawd, nyob rau hauv tej yam adsorption drying txheej txheem, no co- teeb meem adsorption yuav tsum tau txiav txim siab. Siv molecular sieves tuaj yeem tswj tau qhov tshwm sim no vim tias molecular sieves muaj ntau yam sieves nrog txawv pore diameters, thiab los ntawm kev xaiv ib tug haum molecular sieve nrog tsim nyog pore diameters, cov raw khoom Cheebtsam tsis tuaj yeem nkag mus rau hauv tab sis tsuas yog adsorb dej los tswj cov co-cov teeb meem adsorption. Piv txwv li, nyob rau hauv sib sib zog nqus txias sib cais ntawm raw roj rau roj av olefins, 3A hom molecular sieves yuav siv tau los tshem tawm dej thaum lub olefins tsis adsorbed.
Siv lub txaj ruaj khov ntawm molecular sieves rau kev ziab roj yog cov txheej txheem adsorption ib txwm, thiab nws tuaj yeem tsim kho kom ntseeg tau siv cov ntaub ntawv ntawm qhov loj ntawm qhov hloov mus rau qhov ntev.
Cov txheej txheem adsorption ntawm cov roj ziab los ntawm molecular sieves feem ntau ua haujlwm hloov nrog ob lossis ob peb kab adsorption. Thaum lub molecular sieve txaj txheej ntawm no adsorption kem ncav cuag saturation rau dej adsorption, lub adsorption kem yuav tsum tau hloov thiab lub regenerated saturated molecular sieve yuav tsum tau adsorbed. Qhov siab dua qhov rov tsim dua tshiab, qhov ua kom tiav ntau dua, tab sis kev siv lub zog kuj ntau dua, thiab lub neej ntawm molecular sieve tseem yuav luv. Yog li ntawd, qhov kub thiab txias yuav tsum tsawg li tsawg tau kom txo tau lub zog noj thiab ua kom lub voj voog rov ua dua tshiab, uas yog qhov zoo rau kev tsim khoom lag luam. Feem ntau, qhov kub thiab txias yog qhov tsim nyog ntawm 200 - 350℃. Lub peev xwm nqus dej ntawm molecular sieves yuav txo qis tom qab ntau qhov kev tsim dua tshiab. Piv txwv li, tom qab 200 regenerations, lub peev xwm nqus dej dav dav yuav poob los ntawm kwv yees li 30%, tab sis yog tias muaj kev rov tsim dua ntxiv, qhov txo qis ntawm cov dej nqus dej yuav qeeb.
CHEMXIN tau koom nrog Molecular Sieve txij li xyoo 2002, dhau 24 xyoo ntawm kev paub hauv chaw tsim khoom, kev txhim kho thiab kev taw qhia kev teeb tsa. Cia peb sib qhia ntxiv thiab kawm ua ke.